AGRICULTURAL  EXPERIMENT  STATION 


UNIVERSITY    OF     CALIFORNIA 

COLLEGE    OF    AGRICULTURE 

BERKELEY 

CIRCULAR  No.  135 
(August,  1915) 


BENJ.    IDE    WHEELER,    PRESIDENT 
THOMAS    FORSYTH    HUNT,    Dean    and    Director 
H.    E.   VAN    NORMAN,    Vice-Director    and    Dean 
University  Farm    School 


OFFICIAL  TESTS  OF  DAIRY  COWS. 

By  F.  W.  Woll  and  Cora  J.  Hill. 

During  the  last  few  decades  there  has  been  an  increasing  tendency 
among  our  dairy  farmers  to  pay  more  attention  to  actual  performance 
and  less  to  pedigree  and  conformation  only,  in  buying  and  selling  pure- 
bred cattle  than  was  formerly  the  case.  This  has  come  largely  as  a 
result  of  the  invention  of  the  Babcock  test  in  1890  and  the  better 
appreciation  of  the  differences  in  the  productive  capacities  of  different 


Fig.  1.  Tilly  Alcartra  123459,  Holstein-Friesian,  owned  by  A.  W.  Morris  &  Sons 
Corp.,  Woodland,  California.  Production  for  one  year,  30,451.4  lbs.  milk,  containing 
951.2  lbs.  butter  fat  (average  tests  3.12  per  cent).  Production  for  90  days,  8,803.7  lbs. 
milk,    containing  289.039   lbs.   fat. 

cows  among  dairy  farmers  brought  about  through  the  application  of 
this  test  and  of  milk  scales  in  dairy  herds.  The  various  breed  associa- 
tions have  shown  their  appreciation  of  this  difference  by  establishing 
so-called  advanced  registers  or  registers  of  merit  for  cows  that  have 
produced  above  certain  quantities  of  milk  or  butter  fat  during  stated 

18391 


periods.  In  order  that  there  should  be  no  question  as  to  the  correctness 
of  these  records  of  production  it  was  found  desirable  that  they  be 
determined  by  a  wholly  disinterested  agency,  and  as  a  result  the  present 
system  of  official  testing  of  dairy  cows  was  gradually  developed,  through 
co-operation  between  various  dairy  breed  associations  and  the  agricul- 
tural colleges  or  experiment  stations  of  the  different  states.  At  the 
present  time  the  Guernsey,  Jersey,  Holstein,  Ayrshire  and  Brown  Swiss 
breed  associations  have  adopted  this  plan  of  official  testing  and  cows 
are  entered  in  their  advanced  registers  on  the  results  of  authenticated 
records  of  production  made  in  official  tests. 

The  tests  are  conducted  by  representatives  of  the  agricultural  col- 
leges in  the  various  states,  who  are  held  responsible  by  the  general 
public  for  the  correctness  of  the  records  made.  It  follows,  therefore, 
in  justice  to  all  concerned  that  the  colleges  must  take  all  possible  pre- 
cautions against  fraud  or  misrepresentation  in  connection  with  the 
tests,  so  that  dairy  farmers  who  buy  stock  largely  on  the  strength  of 
records  made  in  official  tests  may  have  absolute  assurance  that  these 
show  the  exact  production  of  the  cows  at  the  time  the  tests  were  con- 
ducted. Without  this  assurance  the  tests  would  soon  be  of  no  benefit 
to  any  one. 

The  official  tests  and  the  advanced  registry  records  have  been  of  the 
greatest  value  to  breeders  of  dairy  cattle,  both  from  a  financial  point 
of  view  and  as  an  aid  in  their  breeding  operations.  A  good  record  will 
greatly  increase  the  value  of  both  the  cow  herself  and  her  off-spring 
and  near  relatives.  It  will  also  furnish  important  information  for  the 
selection  of  animals  for  breeding  purposes  with  a  view  toward  improve- 
ment in  the  off-spring  and  will  give  definite  proof  of  the  improvement 
that  has  been  secured  through  selection  and  breeding.  As  the  years 
go  by  the  money  value  and  general  importance  of  the  system  of  official 
testing  to  the  dairy  breeder  and  to  the  agriculture  of  our  state  will  be 
likely  to  increase,  and  hence  a  careful  supervision  of  the  tests  will 
become  of  increasing  importance. 

The  agricultural  colleges  have  found  it  necessary  to  adopt  stringent 
rules  for  the  conduct  of  these  tests  and  the  supervisors  detailed  to 
make  the  tests  are  bound  to  observe  these  rules  in  every  detail,  in  order 
to  safeguard  the  good  name  of  the  tests  and  justify  the  confidence  of 
dairy  farmers  or  breeders  in  the  correctness  of  the  records  made  in 
them.     These  rules  will  be  found  at  the  close  of  this  circular. 

Dairy  tests  in  California.  The  official  testing  work  in  this  state 
is  done  by  the  Division  of  Animal  Husbandry  of  the  College  of  Agri- 
culture, the  writer  having  been  placed  in  charge  of  the  work.  Two 
kinds  of  tests  are  conducted,  viz.,  official  and  semi-official.  The  former 
(official  tests)   cover  periods  of  from  seven  to  thirty  or  sixty  consecu- 


—  3  — 

tive  days,  during  which  the  Supervisor  is  present  at  each  and  every 
milking,  watches  the  cows  milked,  weighs,  samples  and  tests  the  milk, 
and  certifies  under  oath  to  the  correctness  of  the  record  of  production 
made  by  the  cow. 

In  the  so-called  semi-official  tests  for  yearly  records,  the  milk  and 
butter  fat  production  of  the  cows  for  two  consecutive  days  every  month 
is  determined  as  in  the  official  tests,  and  the  average  per  cent  of  fat 
for  this  period  is  taken  to  represent  the  average  quality  of  the  milk 
for  the  month.  The  results  of  this  test  are  reported  to  the  secretary 
of  the  breed  association  concerned,  to  whom  the  owner  of  the  cows 
reports  the  daily  milk  yields  on  the  completion  of  each  month;  by 
multiplying  the  average  per  cent  of  fat  in  the  milk  for  the  two-day 
testing  period  by  the  total  milk  production  during  the  month  the  esti- 
mated production  of  butter  fat  for  the  month  is  ascertained.  The  sum 
of  credits  for  the  months  in  a  year  during  which  the  cow  gives  milk 
makes  the  record  for  the  year. 

The  milk  yields  reported  by  the  owner  are  checked  up  in  various  ways 
by  the  respective  breed  associations  so  that  they  are  doubtless,  as  a 
rule,  accurate.  While  the  figures  for  the  production  of  butter  fat  for 
any  one  month  obtained  as  described  may  not  be  absolutely  correct,  the 
yearly  production  calculated  from  the  sum  of  the  monthly  data  will 
be  practically  so,  viz.,  within  at  least  two  per  cent  of  the  actual  pro- 
duction, since  any  errors  that  may  have  occurred  in  the  figures  for 
the  separate  months  through  the  assumption  that  the  average  quality 
of  the  milk  for  the  month  corresponds  to  that  for  the  two-day  testing 
period,  will  be  evened  up  in  the  course  of  a  year  or  of  an  entire  lacta- 
tion period. 

Supervisors.  In  conducting  official  tests  the  College  employs  a 
number  of  young  men,  as  a  rule,  graduates  of  the  Agricultural  College, 
the  Farm  School  or  the  dairy  short  courses  who  are  familiar  with  the 
Babcock  test  and  modern  dairy  methods  and  who,  we  believe,  possess 
the  tact,  integrity  and  strength  of  character  called  for  in  this  work. 
The  supervisors  are  employees  of  the  College  and  of  the  State,  and 
represent  the  College  in  this  work  at  the  ranches. 

Expense  of  tests.  Since  no  special  funds  are  available  to  defray  the 
expenses  connected  with  the  tests  and  as  the  breeders  whose  cows  are 
tested  are  the  chief  beneficiaries  of  the  work  certain  charges  are  made 
for  the  tests  that  aim  to  cover  all  expenses  connected  therewith.  In 
order  to  place  all  dairy  farmers  of  the  state  on  an  equal  footing,  and 
as  a  matter  of  convenience  in  bookkeeping,  flat  rates  have  been  charged 
for  the  conduct  of  dairy  tests  since  November,  1914,  as  follows : 

For  each  2-day  monthly  test $7  50 

For  each  7-day  test __  25  00 

For  each  30-day  test _ 80  00 

For  each  additional  day,  per  day __ -  3  00 

2—18391 


—  4  — 

These  prices  include  all  direct  expenses  of  the  tests  to  the  breeder, 
except  room  and  board  of  the  supervisor  while  on  duty,  and  trans- 
portation to  and  from  depot.  Sulfuric  acid  must  be  furnished  by  the 
breeder,  as  well  as  pint  or  quart  jars  or  bottles  for  keeping  milk 
samples,  and  a  Babcock  tester.  A  Babcock  tester  will  be  furnished 
by  the  College,  if  the  breeder  pays  the  express  charges  on  the  same 
from  Davis  and  return.  The  College  furnishes  all  other  necessary 
apparatus  for  conducting  tests,  like  galvanized  iron  box,  provided 
with  Yale  lock  and  key,  Babcock  test  bottles  and  pipette,  25  cc.  com- 
posite sample  pipette,  acid  measure,  dividers,  milk  scale,  thermometer, 
report  blanks,  etc. 

Number  of  cows  that  may  be  tested.  The  following  statement 
shows  the  maximum  number  of  cows  that  may  be  tested  at  a  time : 


Maximum  number  of  milkings  per  day 

Maximum  number  of 
cows 

Official 
tests 

Semi-official 
tests 

4  times _      ___      ____ 

6 

8 

3  times    ______       ________      _  ._  _  ___      _  _ 

10 

2  times _    _  _         _      — 

15 

If  cows  placed  on  a  test  are  milked  different  numbers  of  times  a  day, 
the  maximum  number  to  be  tested  at  a  time  shall  be  that  allowed  for 
the  larger  number  of  milkings. 

The  numbers  of  cows  given  above  are  as  high  as  a  conscientious  and 
experienced  supervisor  can  test  at  a  time,  when  composite  samples  are 
taken,  the  calculations  kept  up  to  date,  and  the  rules  as  to  the  super- 
vision of  the  tests  are  carefully  observed  in  all  details. 

Making  applications  for  tests.  Applications  for  tests  should  be 
made  directly  to  the  officer  in  charge  of  the  advanced  registry  in  the 
breed  association  concerned.     A  list  of  these  officers  is  given  below : 

Ayrshire  breed Secretary,  C.  M.  Winslow,  Brandon,  Vt. 

Brown  Swiss  breed Secretary,  Ira  Inman,  Beloit,  Wis. 

Guernsey  breed Secretary,  Wm.  H.  Caldwell,  Peterboro,  N.  H. 

Holstein-Friesian  breed— Superintendent,  M.  H.  Gardner,  Delavan,  Wis. 
Jersey  breed-— Secretary,  R.  M.  Gow,  324  W.  Twenty-third  St.,  New  York 

The  owners  should  also  arrange  with  the  writer  or  with  Miss  C.  J. 
Hill,  Assistant  in  Dairy  Tests,  Budd  Hall,  Berkeley,  Cal.,  for  the  con- 
duct of  tests,  at  least  a  week  before  it  is  desired  to  have  these  commence, 
in  order  that  a  supervisor  may  be  in  readiness  when  wanted.  Applica- 
tion for  tests  to  be  conducted  within  a  certain  month  should  be  filed 
before  the  fifteenth  of  the  month. 

Requirements  for  advanced  registry.  The  dairy  breed  associations 
enter  on  their  advanced  registers  all  heifers  and  cows  that  have  produced 


5  — 


above  certain  quantities  of  butter  fat,  or  milk  and  butter  fat,  during 
either  seven  consecutive  days  or  one  year,  as  shown  by  the  reports  of 
official  tests  certified  to  by  the  officer  in  charge  of  dairy  tests  of  the 
College  of  Agriculture  concerned.  The  following  table  shows  the 
requirements  for  admission  to  the  advanced  registers  of  the  various 
breed  associations  at  the  present  time. 

REQUIREMENTS   FOR   ADMISSION   TO   THE   ADVANCED    REGISTERS   OF 
BREED   ASSOCIATIONS. 


Age 


Ayrshire. 
Year  record. 


Pound3 
milk 


Pounds 
butter  fat 


Brown  Swiss. 
Year  record. 


Pounds 
milk 


Pounds 

butter 

fat 


Guernsey.  Holstein 


Year 
record. 
Pounds 

butter 
fat 


7 -day 
record. 
Pounds 

butter 
fat 


Jersey 


7-day 
record. 
Pounds 
butter 
fat 


Year 
record. 
Pounds 

butter 
fat 


2  years 

3  years 

4  years 

5  years 

6  years 
Pounds 

per    day 
minimum 


6,000 
6,500 
7,500 
8,500 


214.3 
236.0 
279.0 
322.0 


increase 
over 


tl.37 
and 

$2.74 


f.08 
and 
$.12 


*6,0OO 
6,430 
7,288 
8,146 
9,000 


2.35 


*222.0 
238.5 
271.3 
304.2 
337.0 


.09 


*250.5 
287.0 
323.5 
360.0 


*2*  years.     tFor  cows  in  2-year-old  form.     JFor  cows  in  3-year-old  form. 


7.2 

8.8 

10.4 

12.0 


.00439 


12.0 
12.0 
12.0 
12.0 


250.5 
287.0 
323.5 
360.0 


There  is  no  increase  in  the  requirements  for  any  breed  after  a  cow 
is  five  years  old,  except  in  case  of  the  Brown  Swiss  breed  where  six 
years  is  fixed  as  the  full-age  form.  The  age  of  a  cow  is  taken  at  the 
beginning  of  the  record  in  the  case  of  the  Guernsey,  Jersey,  Ayrshire 
and  Brown  Swiss  breeds,  while  in  the  case  of  Holstein  cows  it  is  taken 
at  the  time  of  last  calving. 

Tests  of  grade  cows.  While  the  cost  of  dairy  tests,  as  a  rule,  pre- 
cludes the  testing  of  other  than  pure-bred  cows,  it  is  often  possible  to 
include  also  some  grade  cows  on  the  test  when  only  a  few  cows  are 
tested,  and  dairy  farmers  are  urged  to  test  all  such  cows  which  are 
large  producers,  as  a  year's  record  will  greatly  increase  both  their  own 
value  and  that  of  their  off -spring.  In  order  to  assist  breeders  and  dairy 
farmers  in  securing  records  of  all  good  dairy  cows  irrespective  of  their 
breeding,  the  College  will  arrange  to  supervise  and  certify  to  tests  of 
grade  and  other  cows  for  yearly  records  of  production  under  similar 
conditions  as  those  adopted  for  the  conduct  of  yearly  tests  for  pure- 
bred cows.         f 

Official  tests  of  dairy  cows,  1914-15.  The  number  of  tests  of  pure- 
bred cows  conducted  for  breeders  in  the  state  during  the  year  ending 
May  1,  1915,  was  considerably  higher  than  during  previous  years.  The 
total  number  of  cows  whose  production  of  milk  and  butter  fat  was 
determined  was  567,  against  428  during  the  preceding  year,  an  increase 
of  over  32  per  cent.     Of  this  number,  289  cows  were  tested  once  a  month 


—  6  — 


for  one-year  records,   while  287   cows,   nearly  all  Holstein-Friesians, 
were  tested  for  7-day  records,  and  a  few  for  14  or  30-day  records. 

The  names  of  breeders  for  whom  tests  were  conducted  during  the 
year,  and  the  number  of  cows  tested  in  every  case,  are  shown  below : 


Number  of  cows  on  test  for  period  given 

Tear 

7  days 

14  days 

30  days 

Total 

Ayr  shires : 
University  Farm,  Davis  _._ 

2 

7 

40 
2 
7 
5 

2 

Guernseys : 
Elliott-Brant  Rancho,  Owensmouth 

7 

W.  H.  Dupee,  Santee 

40 

Clayton  R.  Grice,  Del  Mar___    __    

2 

Wm.  H.  Saylor,  San  Francisco___ 

7 

University  Farm,  Davis  ______ 



5 

6 
9 
8 
3 
8 
3 
8 
5 
1 
5 
21 
3 
8 
6 
68 
5 
15 
1 
1 

12 

18 

14 

1 

7 

8 

Holstein-Friesians : 
K.  W.  Abbott,  Milpitas    — _      

61 
6 

B.  F.  Anderson,  Modesto 

8 

17 

J.  W.  Benoit,  Modesto 

8 

H.  E.  Cornwell,  Modesto    . 

3 

J.  S.  Gibson,  Williams. 

8 

W.  H.  Ginn  &  Son,  Corcoran__  _  _    

3 

R.  F.  Guerin,  Visalia . 

1 

9 

J.  H.  Harlan  Company,  Woodland 

2 

7 

Frank  Hatch,  Modesto . 

1 

Geo.  S.  Hewitt,  Hardwick 

5 
7 

10 

Miss  M.  M.  Holdridge,  Modesto __ 

"~2~ 

3 
3 

31 

Fred  Keisel,  Sacramento 

8 

C.  H.  Lindley,  Santa  Cruz 

8 

A.  A.  Merkley,  Sacramento    . 

6 

A.  W.  Morris  &  Sons  Corp.,  Woodland—- 
E.  0.  McClure,  Modesto 

63 
2 

2 

13 

146 
7 

James  McGillivray,  Sacramento 

3 

4 

22 

Preston  School,  lone 

1 

H.  and  R  Rowles,  Modesto 

1 

James  McAlister  &  Son,  Chino 

12 

Geo.  A.  Smith,  Corcoran 

1 

19 

F.  Stenzel,  San  Lorenzo 

14 

University  Farm,  Davis 

Alex  Whaley,  Tulare 

7 

1 

9 

7 

Whittier  State  School,  Whittier 

4 
5 

12 

Jerseys: 
California  Polytechnic  School,  San  Luis 
Obispo                                                 

374 
5 

2 

2 

J  A  Goodall,  Turlock 

7 
18 
13 
15 
18 
14 
1 

22 
1 
7 
7 

7 

W  J  Hackett,  Ceres 

18 

13 

N.  H.  Locke  Company,  Lockeford 

C   G   McFarland,  Tulare 

15 

i     ■ 

18 

G  H  Miller  Modesto 

I 

14 

M  F  Nolan,  Gardena 

1 

1 

C  N  Odell   Modesto 

22 

1 

7 

R  L  Waltz,  Hanford 

7 

130 

SUMMARY  OF  OFFICIAL   DAIRY  TESTS, 

1914-15. 

Breed 

Total 
number 

of 
breeders 

Total 
number 
of  cows 

tested 

Ayrshire   _                   

1 

5 

25 
13 

2 

Guernsey      _  __         _____                   _             _    __ 

61 

Holstein                __  _                _  _    __                 _  __        ______ 

374 

Jersey 

130 

Totals 

*44 

567 

(41    different  breeder 


Fifteen  of  the  7-day  records  made  during  the  year  came  above  21  lbs. 
of  butter  fat,  and  three  were  above  24  lbs.  Two  of  the  latter  are  larger 
than  any  7-day  record  made  last  year,  viz.,  Tula  De  Kol  Pietertje  Neth- 


2.      Fidessa  Bloom,  Holstein-Friesian,  owned  by  Miss  M.  M.  Holdridge,  Modesto, 
Record  for  7  consecutive  days  at  8  years  old,  571.5  lbs.  milk,  26.831  lbs.  butter 


Fig 
California 
fat   (average  fat  content,   4.69   per   cent) 


erland  106233,  567.7  lbs.  milk,  27.057  lbs.  butter  fat,  average  per  cent 
4.75,  and  Fidessa  Bloom  110841,  571.5  lbs.  milk,  26.831  lbs.  butter  fat, 
average  per  cent  4.69.  Both  of  these  cows  were  owned  by  Miss  M.  M. 
Holdridge,  Modesto.     (See  Fig.  2.) 

A  third  7-day  record  may  also  be  mentioned,  viz.,  that  of  Tilly 
Alcartra  123459,  owned  by  A.  W.  Morris  &  Sons  Corp.,  Woodland, 
632.3  lbs.  milk,  24.162  lbs.  butter  fat,  average  fat  content  3.82  per  cent. 
This  cow  also  has  another  record  which  is  the  most  noteworthy  of  any 
made  during  the  year,  viz.,  the  largest  authenticated  milk  production 
for  a  year  by  a  cow  of  any  breed,  30,451.4  lbs.  milk;  this  quantity  of 
milk  contained  951.87  lbs.  butter  fat.     So  far  as  is  known  this  establishes 


the  world 's  milk  record  for  this  period.  The  facts  that  the  cow  finished 
the  year's  test  in  excellent  condition,  that  she  dropped  a  strong,  healthy 
bull  calf  about  two  months  after  the  completion  of  the  test,  and  that 
she  produced  289.04  lbs.  of  butter  fat  on  an  official  90-day  test  during 
the  subsequent  lactation  period  render  the  year's  record  a  still  more 
creditable  accomplishment.      (See  Fig.  3.) 

A  new  state  record  for  the  Jersey  breed  has  been  established  during 
the  year  by  the  cow,  Pearl  of  Venadera,  208644,  owned  by  Guy  H. 
Miller,  Modesto,  producing  11,723.9  lbs.  of  milk  and  702.69  lbs.  of  butter 
fat,  equivalent  to  about  826  lbs.  of  commercial  butter.     (See  Fig.  4.) 

Rules  governing  the  conduct  of  dairy  tests.  The  rules  that  have 
been  adopted  for  the  testing  of  dairy  cows  by  the  different  breed  associ- 


Fig.  3.  Tula  De  Kol  Pietertje  Netherland,  Holstein-Friesian,  owned  by  Miss  M.  M. 
Holdridge,  Modesto,  California.  Record  for  7  consecutive  days  at  7  years  old,  569.7  lbs. 
milk,  27.057  lbs.  butter  fat   (average  fat  content,  4.75  per  cent). 

ations  differ  slightly ;  they  are  given  on  the  report  blanks  or  printed 
circulars  issued  by  the  associations.  In  addition,  this  College  has 
adopted  certain  directions  for  supervisors  in  conducting  dairy  tests, 
which  are  given  below.  These  are  substantially  the  same  as  are  in 
force  in  other  states  and  under  which  official  tests  have  been  conducted 
in  this  country  during  the  past  twenty  years.  Breeders  for  whom  tests 
are  conducted  are  urged  to  co-operate  with  the  College  in  the  enforce- 
ment of  these  rules ;  it  is  primarily  to  their  advantage  that  the  good 
name  of  the  dairy  tests  shall  not  be  allowed  to  suffer  through  a  lack  of 
care  in  the  supervision  of  the  tests  or  a  failure  to  observe  the  precau- 
tions that  experience  has  shown  to  be  necessary  in  their  conduct.  The 
rules  follow: 


1.  The  Supervisor  shall  be  present  at  the  last  regular  milking  pre- 
ceding the  beginning  of  the  test  and  shall  satisfy  himself  that  the  cow 
is  milked  dry  at  that  time.  He  shall  note  the  hour  at  which  the  milking 
is  made,  and  the  final  milking  on  the  test,  whatever  its  length,  must  be 
at  exactly  the  same  hour  of  the  day. 

2.  He  must  be  present  at  each  and  every  milking  of  the  cow  on  the 
test  during  its  progress  and  must  satisfy  himself  that  at  the  close  of 
each  milking  the  pail  contains  nothing  but  the  milk  drawn  from  the  cow. 


Fig.  4.  Pearl  of  Venadera,  Jersey  208,644,  owned  by  Guy  H.  Miller,  Modesto,  Cali- 
fornia. Highest  record  for  production  of  butter  fat  for  one  year  for  Jerseys  in  the  State. 
702.69  lbs.,  equivalent  to  826  lbs.  commercial  butter. 

3.  Under  no  circumstances  shall  more  than  one  cow  undergoing  tests 
be  milked  at  the  same  time.  The  Supervisor  must  in  every  case  be  in  a 
position  to  observe  the  milker  during  the  progress  of  the  entire  milking. 

4.  Immediately  after  the  milk  is  drawn  at  each  milking  he  shall  take 
charge  of  the  pail  and  contents,  weigh  the  same  on  scales  provided  by 
the  Station,  and  enter  the  exact  weight  of  milk  at  once  on  his  records. 

5.  As  soon  as  the  milk  has  been  weighed,  it  shall  be  thoroughly  mixed 
by  pouring  it  from  one  pail  to  another,  or  by  means  of  a  dipper,  and 
a  pint  fruit  jar  immediately  filled  about  two-thirds  full  of  milk  for  the 
test  sample.  The  Supervisor  takes  charge  of  and  is  personally  respon- 
sible for  this  sample  which  must  be  kept  under  lock  and  key  until  tested. 
The  test  is  proceeded  with  as  soon  as  convenient  after  the  milk  has 
cooled  to  ordinary  room  temperature. 

6.  The  Supervisor  shall  make  duplicate  fat  determinations  of  every 
milking  during  the  progress  of  the  test  and  both  determinations,  as 


—  10  — 

well  as  the  average,  are  recorded.  The  sample  taken  of  any  one  milking 
must  not  be  thrown  away  until  a  perfectly  satisfactory  test  of  the  milk- 
ing has  been  obtained.  Readings  of  the  results  are  made  at  a  tempera- 
ture of  130  to  140°  F.  In  case  of  hand  machines  or  electric-driven 
testers  the  test  bottles  are  preferably  placed  for  a  few  minutes  in  a 
small  tin  pail  containing  water  of  this  temperature  before  the  readings 
are  taken.  If  duplicates  vary  more  than  .2  per  cent  the  test  must  be 
repeated. 

On  completion  of  each  test  the  Supervisor  shall  enter  at  once,  in  ink 
or  indelible  pencil,  the  results  obtained  on  the  proper  blanks.  In  mak- 
ing entries  of  the  yield  of  fat,  three  decimal  places  .shall  be  recorded. 
If  the  figure  in  the  fourth  place  be  a  5  or  greater  than  5,  he  shall  increase 
the  third  decimal  figure  by  one ;  but  if  the  fourth  figure  be  less  than  5, 
no  increase  is  made  in  the  third  decimal  figure. 

7.  If  any  of  the  milk  or  the  test  sample  from  a  milking  be  accidentally 
lost,  the  missing  weight  of  the  milk  or  the  fat  credited  to  this  milking 
shall  be  estimated  by  taking  the  average  of  the  four  nearest  milkings 
during  the  test;  if,  e.  g.,  the  evening  milking  is  lost  or  the  test  sample 
therefrom,  the  average  weights  of  milk  or  fat  of  the  four  nearest  even- 
ing milkings  during  the  test  is  to  be  taken  as  the  yield  of  milk  or  fat 
for  the  lost  milking.  It  must  be  stated  on  the  report  that  the  figures  so 
obtained  are  estimated  and  not  actual. 

8.  Composite-test  sample.  At  the  time  the  test  samples  of  the  milk 
are  measured  out  a  sample  comprising  as  many  cubic  centimeters  as  the 
number  of  pounds  in  the  milking,  or  a  multiple  thereof,  is  placed  in  a 
clean  pint  fruit  jar  containing  a  small  quantity  of  preservative,  for  the 
composite-test  sample  to  be  forwarded  to  the  station  on  completion  of 
the  test.  A  25  cc.  glass  pipette  for  taking  this  sample  is  furnished  in 
every  outfit. 

The  Supervisor  shall  be  responsible  for  the  proper  care  and  handling 
of  the  composite  sample,  and  shall  forward  it  to  University  Farm,  Davis, 
Cal.,  immediately  on  the  completion  of  the  test. 

9.  The  Supervisor  shall  fill  out  all  blanks  required  by  the  Station  and 
the  respective  breed  associations  on  completion  of  the  test,  and  shall 
forward  these  promptly  for  verification  to  the  officer  of  the  Station  in 
charge  of  dairy  tests.  A  copy  of  the  results  of  the  tests  shall  be  left 
wTith  the  owner  of  the  cows. 

10.  The  Station  representative  is  not  at  liberty  to  decide  which  stipu- 
lations contained  herein  are  essential  and  which  are  not,  but  is  required 
to  observe  these  directions  in  every  detail.  He  shall  report  at  once  to 
the  officer  of  the  Station  in  charge  of  dairy  tests  any  irregularity  or 
unusual  occurrence  in  connection  with  the  test  that  he  may  observe,  and 
shall  in  general  take  all  possible  precautions  to  conduct  a  fair  and  equit- 
able test  of  the  cows  placed  under  his  supervision. 

o 


